This series of videos says it's original hardware: https://www.nicovideo.jp/watch/sm7111789.

From video description with [added translation]: キャプチャ環境 [capture environment] X68000 ACE-HD→XPC-4(D端子出力 [D-Terminal output])→MonsterX-i

The possible offending sound effect is at 10:45ish. Looks like it's the screech of the fiery griffins.